1. Technical Field
This invention relates to portable temporary tent-like constructions used to temporarily enclose a work area for maintenance or construction related actions so as to be shielded from the environmental elements. Such constructions are also used as containment enclosures preventing contaminants from being released from the enclosure into the environment.
2. Description of Prior Art
Prior art devices of this type have been directed to a variety of containment systems and constructions, see for example U.S. Pat. Nos. 2,335,274, 3,121,470, 4,739,592, 4,787,178, 4,926,892 and 7,134,444.
U.S. Pat. No. 2,335,274 discloses a portable welding screen having multiple supports bolted together along a single plane to form a safety screen.
U.S. Pat. No. 3,121,470 claims a protective covering for a scaffold wherein a flexible sheet of material overlies and is secured to the vertical support elements of a scaffolding.
U.S. Pat. No. 4,739,592 illustrates a protective awning for a scaffolding and tubular structure having a sheet of covering material fitted on the bearing structure formed from tubular elements. A tightening mechanism allows for tightening of the sheet so as to be secured thereon and thereover.
U.S. Pat. No. 4,787,176 discloses an abrasive blasting containment system wherein an enclosure is formed by a tubular support frame on which flexible material is attached.
U.S. Pat. No. 4,926,892 claims a temporary enclosure structure formed of interengaging tubular framed elements and side frame sections of vertical and horizontal members with multiple pipe sections oriented therewith.
Finally, in U.S. Pat. No. 7,134,444 an environmental containment unit is disclosed having a portable enclosure providing a flexible envelope attached to an interior support of vertical and horizontal collapsible frame elements.